The ITER cryostat provides a vacuum environment to avoid excessive thermal loads from being applied to the components that operating at cryogenic temperatures.A global mechanical analysis is required to have simulation information to check the structural reliability of the design for its complex working condition.Finite element model was established,and the mechanical analysis of the ITER cryostat was performed under some typical working conditions.The stresses and displacements are within allowable design requirements.The analysis results indicate the teasibility of the ITER cryostat structure.